In addition, it was also found that while CSF CXCL13 levels differed significantly between the MS and control groups in another study, no such differences were found between the RRMS and PPMS group in the stable phase of MS without relapse, despite these two subtypes of MS representing different stages of neurodegeneration (Iwanowski et al., 2017). Here, CXCL13 is linked to myeloid sarcoma.